Field of the Invention
The present invention relates to information processing of performing gesture recognition.
Description of the Related Art
User interfaces (UIs) capable of input by a gesture are used in many different fields. A tabletop interface is known as one of the gesture input UIs. In the tabletop interface, display contents or behaviors to a gesture input need to be switched based on which among, for example, four sides of a table is the side where the gesture input has been done and the angle of the gesture input with respect to the side (to be referred to as “user's position and orientation” hereinafter).
Especially, when recognizing a gesture, feature amounts detected by the user's position and orientation largely change, and recognition needs to be performed by classifying gestures according to user's positions and orientations. However, recognition of classified gestures is done using gesture learning data of the respective classes, and the necessary data amount increases. Additionally, it is difficult to appropriately define criteria to classify the user's positions and orientations. For these reasons, it is demanded to dynamically transform detected feature amounts into a coordinate system according to the user's position and orientation for each gesture input.
There is known a technique of detecting, from a captured image of a projection screen, a direction (insertion direction) in which a user's hand is inserted into the image projection screen, and determining the display position and orientation of a UI in accordance with the insertion direction. According to this technique, it is possible to dynamically determine a UI display coordinate system according to the user's position and orientation and transform detected feature amounts into a coordinate system independent of the user's position and orientation. That is, it is possible to obtain feature amounts independent of the user's position and orientation and recognize a gesture using them.
However, not only linear gestures of inserting a hand in the projection screen and removing the hand from the projection screen but also a gesture of, for example, waving an object (manipulation object) such as an arm used for a gesture on the projection screen is possible. Considering such a gesture, it is impossible to determine the coordinate system according to the user's position and orientation using the above-described technique of determining the coordinate system based on the insertion direction.